Clematis Container Growing Clematis performs best in large pots, especially if you live in a climate with chilly winters; the extra potting soil in a larger pot provides protection for the roots. Nearly any pot with a drainage hole is fine, but a ceramic or clay pot is likely to crack in freezing weather.Click to see full answer. Also know, what are the best clematis to grow in pots? The best clematis to grow in containers in the small garden The best varieties include: Fleuri, with its very deep velvety purple flowers and the deep purple- blue Chevalier; it produces single, semi-double, and fully double flowers at the same time on the same plant.Furthermore, how do you overwinter clematis in pots? Overwintering clematis plants in pots is possible even in the coldest climates. If your container will not tolerate freezing temperatures, move it to a place where it will not freeze. If the clematis is healthy and in a freeze-safe container that is at least 2 feet in diameter, you do not have to provide mulch. Secondly, what can I feed my potted clematis? Spread a slow-release, potassium-rich fertiliser around the base of the plant, such as a rose fertiliser or specialist clematis fertiliser. Apply a mulch afterwards of organic matter such as well-rotted manure or compost. For the best flowering make sure you feed your clematis in late winter or early spring every year.What is the best time of year to plant a clematis?Clematis, like most plants, is best transplanted on cool, overcast days, in fall to early spring. Your first step will be to dig a hole at least 18 inches deep and 18 inches wide for the clematis.